Fully coupled fluid-structure-contact simulations to understand the processes in the contact zones during lubricated orthogonal cutting

在金属切削加工中，减少冷却润滑剂（CL）的消耗具有特别大的可持续性潜力，因为冷却润滑剂对环境和健康造成损害，而且成本高昂。为了在冷却液量减少的情况下保持生产率并确保所需的部件质量，未来必须更有针对性地使用冷却液。特别是，在利用冷却剂的摩擦学效应方面有很大的潜力。为了在机械加工生产中利用这一点，必须详细了解潜在的作用机制，并在数字化工具中考虑到这些机制，以进行工艺和工具开发及其优化。在优先项目SPP 2231框架内的这一后续项目的背景下，为此目的，将在考虑数值切屑形成模拟的CL的情况下进行摩擦建模的改进。这是通过将微观摩擦学模型与宏观切屑形成模型耦合来实现的，并且提供了将切屑形成区中的摩擦作为温度、相对速度、接触法向应力以及摩擦伙伴和中间介质的表面形貌的函数来建模的可能性。为了获得建模的技术理解和数据，并为以后转移到工业生产奠定基础，计划对切屑形成区的摩擦学行为进行额外的基础研究。在该项目的第一阶段，进行了冷却润滑剂的工作机制的实验研究，并已成功地开发了一个微观摩擦学模型的芯片形成区，这应该使人们有可能调查这些机制在实验上无法访问的规模，并使它们可用于芯片形成模拟。微观模型是基于流体-结构接触模拟，使用基于样条的有限元方法。在下一个项目阶段，计划将微观摩擦学模型与切屑形成模型相结合。这种耦合将允许在考虑CL的局部分级的数值切屑形成模拟中对摩擦行为进行建模。为了能够实现这一目标，深入的实验研究的影响分析和模拟验证的目标是必要的。除了应用切屑形成区中冷却剂分布可视化方法外，还特别包括粘附和滑动区的表征以及加工过程中局部机械载荷的确定。最后，在筹备第三个供资阶段时，试验性框架将转入转向进程。

In metal-cutting manufacturing, a particularly large sustainability potential can be found in reducing the consumption of cooling lubricants (CL), which cause damage to the environment and health as well as high costs. In order to maintain productivity and ensure the required component quality despite the reduction in coolant quantities, the use of coolant must be more targeted in the future. In particular, there is great potential in exploiting the tribological effect of the coolants. In order to utilize this in machining production, the underlying mechanisms of action must be understood in detail and taken into account in digital tools for process and tool development and their optimization.In the context of this follow up project in the framework of the priority project SPP 2231, developments for the improvement of friction modeling under consideration of a CL for numerical chip formation simulations will be performed for this purpose. This is achieved by coupling a microscopic tribology model with a macroscopic chip formation model and offers the possibility to model the friction in the chip formation zone as a function of temperature, relative speed, contact normal stress as well as surface topographies of the tribo-partners and an intermediate medium. In order to gain the technological understanding and the data for the modeling and to lay a basis for the later transfer to industrial production, additional basic investigations on the tribological behavior of the chip formation zone are planned. In the first phase of the project, experimental investigations of the working mechanisms of cooling lubricants were carried out and it has been succeeded to develop a micro-tribological model of the chip formation zone, which should make it possible to investigate these mechanisms on an experimentally inaccessible scale and make them usable for chip formation simulations. The micro-model is based on a fluid-structure contact simulation using spline-based finite element methods. In the next project phase, the coupling of the micro-tribological model with a chip formation model is planned. This coupling will allow to model the friction behavior in the numerical chip formation simulation locally graded considering a CL. To be able to achieve this goal, in-depth experimental investigations with the objectives of influence analysis and simulation validation are necessary. In addition to the application of a method for the visualization of the coolant distribution in the chip formation zone, these include in particular the characterization of the sticking and sliding zone as well as the determination of the local mechanical loads during machining. Finally, in preparation for the third funding phase, the experimental framework shall be transferred to a turning process.